My 97 XJ6 has 103K and is letting me know it needs attention to the timing chain tensioners with noise from 1500 - 2000 RPM. From an examination of the hydraulic piston that is replaceable from outside, it appears to be the "new" style cap. I'm running 20W-50 Mobile 1 oil. I think I'm looking at $1500 for replacement of the tensioners given all that is involved in the job. Anybody else been down this road? Share your experience.

 

Did mine at 145k kms, and it had the "new style" top unit, but the supplier here has been selling quite a few lately, and there was noticeable scuff marks on the piston and the cylinder.
A new unit "fixed it" to a dergree, but I went further and repalced the chains, blades, and lower tentioner piston assembly, inc oil pump chain and its damper.

It is "better" but by no means as quiet as I would expect, and dead set noisier than any XK 6 cyl engine I have owned/heard, and waaaaay noisier than either of my V12's, one of which is nudging 500k kms.

Much asking, and it appears to be real common, and is just how it is, dunno.

 

I am relatively fresh off having replaced the tensioners and guides (dampers) on a 4 litre supercharged AJ16. A friend thinks the front cover could be removed without removing the cylinder head, but I remain unconvinced... Getting the sealant to adhere at the top and bottom of the cover seems unlikely without removing the head, but I wonder if anyone has tried? It sounds like you are planning to have the work done by a trusted garage? If so, I would expect the cost to be fairly high as it is a time consuming job considering all of the collateral issues that are likely to arise. If I could make a suggestion, unless they are clearly worn out, I would not replace the chains; rather just the guides and tensioners. I noted that the chains and gears were not appreciably worn even with 220'000 kms on this engine. I replaced only the tensioners and guides and all is now quiet and smooth. Mind you, I also replaced the cylinder head as a brand new one was made available! The guides had worn down to the metal on both the upper and lower tensioner sides, and the other guides were heavily grooved. Replacement of these items was indeed warranted. However, I am thinking the chains will likely outlast the car if oil change intervals are followed.

If there is anything else you are curious about, ask away. I have some photos of the job I could post if needed.

 

this might help - http://tinyurl.com/335pl35 - and yes, it can be done without removing the head.

Not to be undertaken lightly though - especially if you are paying someone else to do it for you!

Best wishes from Jim Butterworth
http://www.watchet.dolphins.btinternet.co.uk/

 

That's a little gold mine of info you have there Mr Butterworth! Bookmarked for safe keeping. I would second your suggestion to use good 6 point sockets on all the bolts, especially the AC compressor bolts! Little beggars are really tough to break loose. Whose bright idea was it to put 10 mm heads on such large bolts? There oughta be a law...

 

HAH, that bolt was a special design by that well known demon, MURPHY. He abodes in all things JAGUAR.

 

I hear you. Murphy seems to lurk in everything. The best Murphy repellent is to never be impatient, and always have the right tool for the job. Most screw ups are avoided by simply getting up and walking over to the tool box and selecting the appropriate tool. Barring that, go buy, borrow or make one. But whoever decided to use those bolts should have been incarcerated in their youth.

 

I can't believe it was not quiet after the service!

 

If the "timing chain" noise is still present at 1500-2000 rpm after renewing the timing chains and guides - could the front cat be rattling I wonder ?

Just a thought - and carefully check around the exhaust heat shileds in case one is resonating ?

Best wishes from Jim Butterworth
http://www.watchet.dolphins.btinternet.co.uk/

Just because you're not paranoid doesn't mean they're not out to get you